What does digital cone ct mean?

Cone-beam CT is the most promising and practical equipment in oral skull imaging equipment. The application of cone-beam CT has brought revolutionary changes to the diagnosis and treatment of oral cavity and skull clinical field. American ADA predicts that there will be at least 654.38 million+units in the world in the next five years.

Cone-beam CT, as its name implies, is a computer tomography device using cone-beam projection. The principle is that the X-ray generator makes a circular DR (Digital Projection) around the projector with a low amount of rays (usually the tube current is about 10 mA). Then, after digital projection around the projector for many times (180 -360 times, depending on different products), the data obtained at the "intersection" is "reconstructed" in the computer to obtain a three-dimensional image. The data projection principle obtained by CBCT is completely different from the traditional sector scanning CT (see figure B below), but the algorithm principle of computer reorganization in the later stage is similar.

The biggest difference between CBCT and CT (spiral CT) is that the projection data of CT is one-dimensional, and the reconstructed image data is two-dimensional. The reconstructed three-dimensional image is composed of multiple continuous two-dimensional slices, and the image metal artifacts are heavy. The projection data of CBCT is two-dimensional, and three-dimensional images can be obtained directly after reconstruction. From their imaging structure, CBCT uses three-dimensional cone-beam X-ray scanning instead of two-dimensional fan-beam scanning of tomography; Accordingly, CBCT uses a two-dimensional planar detector instead of a linear detector for tomography. Obviously, CBCT cone-beam X-ray scanning can significantly improve the utilization rate of X-rays, and all the original data needed for reconstruction can be obtained by rotating 360 degrees, and the data acquisition speed can be accelerated by collecting projection data with area detector. Another advantage of CBCT is its high isotropic spatial resolution.

Compared with traditional sector scanning CT, cone beam CT has the following advantages:

1. Radiation is extremely low.

Compared with traditional multi-slice spiral CT, one projection of NewTom cone-beam CT is only equivalent to 1/30- 1/40 of traditional CT, and only equivalent to four digital surface tomography projections. -An American research report pointed out that the dose of a CBCT (36.9uSv) is only equivalent to that of a whole-mouth apical slice (about 13- 100uSv). Most patients in orthodontics department are children, and their radiation absorption capacity is 10 times that of adults. In the field of orthodontic treatment, CBCT with extremely low radiation undoubtedly has great advantages over traditional CT. At the same time, the early diagnosis of airway ventilation disorder in children by using CBCT owned by stomatology undergraduates can make most children's occlusal deformities be treated in time.

2. The application range is extremely wide.

NewTom 12-inch cone-beam CT can be widely used in oral and maxillofacial surgery, orthodontics, orthognathic surgery, implant surgery, dentistry, temporomandibular joint, otorhinolaryngology. Although traditional CT has some oral software to choose from, it is expensive and not as humanized as CBCT special oral software. Stomatological hospitals and general hospitals equipped with large-field cone-beam CT can make rapid development in implant, root canal (tooth), orthodontics, orthognathic surgery, periodontal and other fields in a short time.

3. The application of stomatology is more convenient.

According to the experience of CBCT's former clients (such as Beijing 30 1 Hospital), although traditional CT can obtain most of the three-dimensional images of the head needed by stomatology, CBCT in stomatology itself has unparalleled advantages in generating personalized images such as visual field selection and image synthesis. Many research institutions have compared the imaging effects of CBCT and whole-body CT (including spiral CT and multi-slice CT) on oral and maxillofacial structures. The results show that CBCT has high spatial resolution, and CBCT has better imaging quality for high-resolution areas such as mandible, mandibular neural tube and temporomandibular joint. The three-dimensional imaging and multi-directional imaging characteristics of CBCT are also helpful for the diagnosis of oral and maxillofacial diseases. Compared with traditional CT, CBCT not only greatly reduces the exposure radiation dose, but also can perform multi-directional, multi-level reconstruction, curved volume reconstruction or three-dimensional reconstruction on the axial image obtained from the initial reconstruction. The continuous longitudinal reconstruction of CBCT can clearly display the vertical images of maxillary and mandibular dental arches, which is a characteristic reconstruction sequence of oral and maxillofacial CT (oral CBCT) which is different from other common CT. In addition, the three-dimensional reconstructed image can also be observed at any angle, and the reconstruction range can be arbitrarily selected. On the three-dimensional reconstruction image, part of bone tissue can be removed by adjusting the window, leaving only a high-density tooth image. Combined with axial images, we can accurately understand the shape, position, relationship with adjacent teeth, displacement or root absorption of adjacent teeth. Therefore, CBCT examination can provide accurate information for clinicians to make further treatment design or preoperative approach selection. Therefore, the use of CBCT can greatly improve the scientific research and clinical level of stomatology.